Method and apparatus for controlling aquatic weed growth



Oct. 6, 1964 D. R. TALBOTT 3,151,463

hliETHGD AND APPARATUS FOR CONTROLLING AQUATIC WEED GROWTH Filed March28, 196, 2 Sheets-Sheet 1 ATTORNEYS Oct. 6, 1964 D. R. TALBOTT 3,151,463

METHOD AND APPARATUS FOR CONTROLLING AQUATIC WEED GROWTH Filed March 28,1962 2 Sheets-Sheet 2 INVENTOR DA v10 R. TALBOTT BY 'zfazi/ume/vs mza/uATTORNEYS United States Patent I David R. Talbott, 224 Westwood Road,Annapolis, Md.

Filed Mar. 28, E52, Ser. No. 183,24il 4 Claims. ((11. 61-4) Thisinvention relates to aquatic weed control and more particularly to amethod and apparatus for inhibiting or preventing the germination andgrowth of aquatic weeds in selected areas.

The marginal shorelines of many bays, tributaries and inland waters,particularly of the United States, support an annual type of aquaticweed which each year during the spring and early summer springs up fromseeds or spores deposited on the bottom by the weed growth of thepreceding year. During the fall and winter months the growth entirelydisappears to reappear in the springtime, first as small seedlings whichmature into a dense, matted almost inpenetrable blanket extending fromthe shoreline outwardly a distance of between approximately 25 and 200feet depending upon the slope of the bottom.

Where the above mentioned belt or blanket or annual weed growth exists,as it does almost universally in certain areas, it is practicallyimpossible for any use to be made of the riparian waters infested by thegrowth. Thus such waters cannot be used for swimming, boating, fishingand the like and it is a broad object of the present invention toprovide a novel method and apparatus which inhibits or prevents theinfestation by weed of selected areas normally rendered unusable becauseof weed growth.

The aquatic weed with which the present invention is concerned is, incommon with substantially all vegetation, dependent upon sunlight forgermination and growth though other factors, such as water temperature,are also essential elements. Where sunlight is shaded from a potentialWeed bed, the weed does not germinate even though all other factors ofgermination are favorable. Though it has been recognized that weedgrowth might be prevented by the use of some form of shading means overthe weed bed, no practical means have been devised which can withstandprolonged submergence or will not interfere with the otherwise normaluse of the waterfront. It is the object of the present invention toprovide a method and apparatus which effects shading of selected bottomareas so as to prevent weed germination, or growth, without any of thedisadvantages of other shading means which might conceivably be employedfor such use.

More specifically, it is the object of the invention to accomplish theforegoing by a novel method and apparatus which effects disturbance oragitation of suspensionable bottom material in an area to be treated soas to cause the material to be placed in suspension in the waterway overthe area and produce a shading cloud through which sunlight cannotpenetrate in sufficient strength to permit the weed spores or seeds togerminate and grow.

Though one function of the method and apparatus of the invention is toproduce the sunlight blocking cloud as mentioned in the foregoingparagraph another object of the invention is to utilize the bottomdisturbing action to maintain in suspension weed spores and seeds sothat by sunlight shading or by seed suspension or by a combination ofboth, germination is prevented in the area undergoing treatment.

Yet another object of the invention is to provide apparatus which, inaddition to accomplishing the above objects, may also be utilized fordistributing chemicals on weed in selected areas.

Other objects and their attendant advantages will become apparent as thefollowing detailed description is 3,151,463 Patented Oct. 6, 1964 readin conjunction with the accompanying drawings wherein:

FIG. 1 is a top plan view of a typical waterfront area showing a form ofapparatus constructed inaccordance with the invention and which may beutilized to treat a selected area in accordance with the method of theinvention;

FIG. 2 is a vertical cross sectional view taken substantially on theline 2-2 of FIG. 1;

FIG. 3 is an enlarged vertical cross sectional view of apparatusconstructed in accordance with the invention; and

FIG. 4 is a broken plan view showing apparatus of another type which maybe employed in accordance with the invention.

In accordance with the method of the invention germination of weed isprevented by the continued or intermittent disturbance or agitation ofsuspensionable bottom material of selected areas subject to weed growthduring the period when the weed seeds normally germinate. This bottomdisturbance prevents germination through one or the other of twoagencies or through a combination of both; namely, the production of asuspended, sunlight shading cloud over the treatment area or thephysical suspension of the weed seeds over the bottom.

FIGS. 1 through 3 illustrate a type of apparatus constructed inaccordance with the invention for accomplishing the foregoing results.FIG. 1 illustrates a typical beach front where it may be desirable toretain an area on one side of a pier 10 free of weed so as to besuitable for swimming, for example. The apparatus illustrated comprisesa series of flexible hoses 12 which may be arranged in spaced parallelrelationship to extend outwardly from the shoreline a desired distanceand have their inner ends connected to a manifold 14 running parallel tothe beach 16 a distance equal to the width of the selected area fromwhich weed is to be excluded. The manifold is supplied with water underpressure by way of a pump 18 whose suction side receives water by way ofa conduit 20 whose outer end is connected to a suitable strainer 22below the waters edge. If desired, the conduit 20 may be connected to asupply reservoir 23 containing chemical weed killer as indicated by thedotted lines.

With reference to FIG. 3 it will be seen that each of r the hoses 12 isprovided throughout its length with a plurality of downwardly andoutwardly extending outlet orifices 24 which are so arranged thatpressurized water within the hose is projected in a series of jetsdiagonally downwardly against the bottom as indicated at 26 in FIG. 3.The hoses 12 are so positioned and spaced with respect to each otherthat the jet streams of adjacent hoses overlap each other as indicatedso that the entire area of the bottom is agitated. In order to anchorthe hoses in their position of use with the orifices properly directed,a plurality of lateral metallic rods 28 may be provided havingintegrally connected thereto at spaced intervals corresponding to thedesired spacing of the hoses a plurality of spring clips 30 which areadapted to frictionally clamp the hoses after their orifices have beenproperly oriented to produce the desired jet action against the bottom.

In operation, it will be observed in FIGS. 2 and 3 that when water underpressure is delivered by the pump 18 to the manifold 14 the water flowsoutwardly through the orifices 24 to impinge on the bottom therebycausing to be jetted into suspension bottom material to form a cloud 34which will generally overlie the treatment area encompassed by thehoses. As illustrated in FIG. 2 this cloud will prevent the sun rays,indicated by the numeral 36, from reaching the bottom thereby excludingfrom the treatment area a necessary factor for seed germination hoses 12illustrated in FIG. 1.

or weed growth. In addition to producing the cloud 34, there Will alsobe jetted into suspension still dormant weed seeds or spores thuspreventing their coming into necessary contact with the bottom forgermination and subsequent sprouting. In order to utilize the bottomdisturb ing action of the apparatus of the invention for the purpose ofjetting seeds into suspension, it will be apparent that the bottom areashould be treated early enough in the spring so that the seeds orseedlings have not obtained a secure rooting in the bottom. In the eventthat a dense growth has accumulated before the commencement oftreatment, it may be desirable to apply chemical weed killer to thegrowth by connecting the pump 18 to the weed killer supply 23. It shouldbe understood that the weed killer may be metered by means of aconventional venturi (not shown) between the pump and strainer Theapparatus disclosed in FIG. 4 differs from that of FIG. 1 in that theformer contemplates the use of pneumatic pressure for producingsubstantially the same results as the apparatus of FIG. 1. The advantageof pneumatic pressure as opposed to water pressure is the fact that airpressure is susceptible of being stored in a suitable reservoir to bemetered outwardly at a steady or intermittent rate as necessary toaccomplish the desired results. It will thus be apparent that thecompressor supplying the reservoir need only operate for short periodsof time suflicient to supply the reservoir with pressure betweenprede.ermined high and low values.

in PEG. 4 the numeral 48 designates a compressor having delivery conduit42 connected to a reservoir The reservoir 44 is provided with an outletconduit 46 leading to a manifold 43 to which there ar connected theinner ends of hoses which may correspond generally to the Desirably,there is provided in the conduit 46 a metering valve 52 which may be ofthe constant flow type or an automatic intermittent type whereby in thelatter instance, pulses of pressurized air are admitted to the manifold43 and hoses 5h. The compressor 40 may be controlled by a conventionalelectro-pneumatic switch 54 responsive to reservoir pressure by way of acontrol conduit 56. It is believed that the operation of the compressorand storage system of FIG. 4 is sufficiently well known to those skilledin the art that a detailed description thereof is not required, it being sufiicient to say that pressurized air passing through the meteringvalve flows through the hoses and outlet orifices in FIG. 3 in the samefashion as the previously described water pressure to producesubstantially the same results.

Intermittent operation of the arrangment of FIG. 1, similar to thepneumatic system of FIG. 4, can be obtained if desirable or necessary bythe use of a water tank having a trapped air head which may beintermittently pressurized in a manner similar to household waterpressure systems which are supplied from individual wells, in whichevent the system would be arranged substantially as the pneumatic systemshown in P16. 4, except that the compressor 40 would correspond to thepump 18 and would include an intake conduit similar to conduit 20.

The invention is by no means limited to the particular arrangement ofhoses illustrated in the drawings inasmuch as the results of theinvention will be achieved with any hose or other conduit arrangement,such as for example a network of hoses or pipes, or a single hose whichis arranged spirally to cover the area which it is desired to treat.Furthermore, the means illustrated for anchoring and positioning thehoses is representative only since obviously other suitable means may beemployed.

In lakes and in sheltered tidal tributaries, current flow is negligibleso that a suspended cloud of bottom material can be maintained over thetreatment area without ditficulties throughout the daylight periods. Inareas where relatively significant current flow exists, the apparatuscan be retained in operation throughout the germinating period so thatseed jetted into suspension is carried by the current away from thetreatment area. The supply of additional seed flowing over the area fromupstream will be progressively decreased as that seed takes root in thenormal manner in spaces outside of the treat ment area. Thus it will beapparent that the apparatus and method of the invention is asadvantageous in areas where there is no current flow as in areas wherethe current is significant.

Though the apparatus of the invention may be installed substantiallypermanently in the treatment area, it is contemplated that the apparatuswill be portable and will be located in the treatment area for only suchlength of time as is necessary to insure non-germination of the weed.This can usually be determined by observing the weed growth in untreatedareas and when it is apparent that the weed growth outside of thetreatment area has grown to a substantial size, operations can beterminated and the apparatus removed. Experiments have established thatwhere established weed growth has con removed by jet action so that theweed roots are disconnected entirely from the bottom (see the patents toTalbott and Darden, Nos. 2,852,868 and 3,019,535 for apparatus foraccomplishing the foregoing) there is no further or later germination ofweed seeds or weed growth so that once treated by the method of theinvention an area remains clear of weed throughout the remainder of theseason.

From the foregoing description, it will be apparent that the apparatusof the invention is susceptible of variety of changes and modificationwithout however departing from the scope'and spirit of the intendedclaim.

What is claimed is:

1. The method of preventing the germination and growth of aquatic weedsin selected areas of waterways whose bottoms are composed of materialsubject to weed growth and suspensionable upon agitation thereofcomprising agitating said bottom material in each of said areas until asuspended sunlight shading cloud of bottom material substantiallyoverlies the entire area and continuing the agitation to maintain saidcloud over said area until the period of weed germination and growth haselapsed.

2. The method of claim 1 wherein the agitation is afforded by subjectingsaid bottom material to a plurality of fluid pressure jets projectedagainst the bottom and distributed uniformly over said area.

3. The method of claim 2 wherein said jets are afforded by waterpressure.

4. The method of claim 2 wherein said jets are afforded by air pressure.

References Cited in the file of this patent FOREIGN PATENTS GreatBritain Nov. 24, 1886 Italy June 26, 1933 OTHER REFERENCES

1. THE METHOD OF PREVENTING THE GERMINATION AND GROWTH OF AQUATIC WEEDSIN SELECTED AREAS OF WATERWAYS WHOSE BOTTOMS ARE COMPOSED OF MATERIALSUBJECT TO WEED GROWTH AND SUSPENSIONABLE UPON AGITATION THEREOFCOMPRISING AGITATING SAID BOTTOM MATERIAL IN EACH OF SAID AREAS UNTIL ASUSPENDED SUNLIGHT SHADING CLOUD OF BOTTOM MATERIAL SUBSTANTIALLYOVERLIES THE ENTIRE AREA AND CONTINUING THE AGITATION TO MAINTAIN SAIDCLOUD OVER SAID AREA UNTIL THE PERIOD OF WEED GERMINATION AND GROWTH HASELAPSED.